Nanoscale Organization of a Platinum(II) Acetylide Cholesteric Liquid Crystal Molecular Glass for Photonics Applications

The fabrication, molecular structure, and spectroscopy of a stable cholesteric liquid crystal platinum acetylide glass obtained from trans‐Pt(PEt₃)₂(C?C?C₆H₅?C?N)(C?C?C₆H₅?COO?Cholesterol), are described and designated as PE1‐CN‐Chol. Polarized optical microscopy, differential scanning calorimetry, and wide‐angle X‐ray scattering experiments show room temperature glassy/crystalline texture with crystal formation upon heating to 165 °C. Further heating results in conversion to cholesteric phase. Cooling to room temperature leads to the formation of a cholesteric liquid crystal glass. Scanning tunneling microscopy of a PE1‐CN‐Chol monolayer reveals self‐assembly at the solid?liquid interface with an array of two molecules arranged in pairs, oriented head‐to‐head through the CN groups, giving rise to a lamella arrangement. The lamella structure obtained from molecular dynamics calculations shows a clear phase separation between the conjugated platinum acetylide and the hydrophobic cholesterol moiety with the lamellae separation distance being 4.0 nm. Ultrafast transient absorption and flash photolysis spectra of the glass show intersystem crossing to the triplet state occurring within 100 ps following excitation. The triplet decay time of the film compared to aerated and deoxygenated solutions is consistent with oxygen quenching at the film surface but not within the film. The high chromophore concentration, high glass thermal stability, and long triplet lifetime in air show that these materials have potential as nonlinear absorbing materials.     

Activating Effect of 3-Benzylidene Oxindoles on AMPK: From Computer Simulation to High-Content Screening

AMP-activated protein kinase (AMPK) is currently the subject of intensive study and active discussions. AMPK performs its functions both at the cellular level, providing the switch between energy-consuming and energy-producing processes, and at the whole body level, particularly, regulating certain aspects of higher nervous activity and behavior. Control of such a ‘main switch’ compensates dysfunctions and associated diseases. In the present paper, we studied the binding of 3-benzylidene oxindoles to the kinase domain of the AMPK α-subunit, which is thought to prevent its interaction with the autoinhibitory domain and thus result in the AMPK activation. For this purpose, we developed the cellular test system based on the AMPKAR plasmid, which implements the FRET effect, synthesized a number of 3-benzylidene oxindole compounds and simulated their binding to various sites of the kinase domain. The most probable binding site for the studied compounds was established by the correlation of calculated and experimental data. The obtained results allow to analyze various classes of AMPK activators using virtual and high-content screening.     

Marginal contribution representation of capacity-based multicriteria decision making

Integrals defined with respect to fuzzy measures (capacities) are powerful tools in multicriteria decision making. Monotonicity is a basic property of capacity, which means that the marginal contribution of any single criterion to any subset of criteria is always nonnegative. In this paper, we present the capacity-based decision making theory in terms of marginal contributions, which provides an alternative perspective to this widely used decision making strategy. We construct the marginal contribution representations of the equivalent transformations of capacities, some particular capacities, three types of nonlinear integrals, and discuss the capacity identification methods. We also introduce some new concepts and representations, such as nonadditivity and nonmodularity indices, 0 to 1 variables-based linear constraints of k-maxitive capacity, a special representation of the Choquet integral and pan integral. We discuss constraints on marginal contributions which ensure supermodularity of capacities. Finally, an illustrative example is given to show the use of marginal contribution presentation in capacity-based decision making methods.     

Plasma–powder application of antifrictional babbitt coatings modified by carbon nanotubes

Modification of Babbitt coatings by carbon nanotubes in plasma–powder application is considered. A model is proposed for the interaction of a graphene-like surface and atoms from the Babbitt alloy. The influence of carbon nanotubes obtained by different means on the performance of antifrictional coatings is studied.     

Effect of Spark Plasma Sintering Temperature on the Properties of Transparent YSZ Ceramics

Refractories and Industrial Ceramics - A transparent submicron-grain sized cubic yttria-stabilized ZrO2 ceramics was obtained by spark plasma sintering in the temperature range from 1200 to...     

Synthesis and properties of rhenium–polyethylene nanocomposite

New rhenium-containing composites were synthesized by thermodestruction of different rhenium complexes. The composites consist of rhenium-containing nanoparticles stabilized by low-density polyethylene matrix. The structure of composites was characterized by means of TEM, EDS, XRD, EXAFS and EMR. Transmission electron microscope images illustrate that the rhenium-containing nanoparticles are 15.0 ± 0.3 nm in size. The particles consist of Re, Re₂O₇, ReO₃ and ReO₂. In the electrophysical measurements it was found that permittivity and attenuation of microwave radiation correlate with composition of rhenium-containing nanoparticles.     

Extraction of ions from a plasma source and formation of beams

The current of ions extracted from a plasma source has been measured as a function of extraction voltage U _e . Comparison of the obtained characteristics to theoretical predictions has shown that the experimental data agree with the Child-Langmuir theory only within a certain range of U _e . The results of our measurements and computer simulation of the ion-beam profile allowed the assessment of the parameters of the ion-emitting surface and the average ion energy in the plasma of the source under study.     

Preparation of C70-Doped Solid Silica Gel via Sol–Gel Process

We reported the first preparation of C₇₀-doped solid gel. Its UV-visible spectrum was recorded.